Advocates say raising the amount of ethanol in gasoline from the current 10% blend to 15% reduces the nation's dependence on foreign oil, lowers the price of fuel and is good for the environment.

Critics say the 15% blend could cause engine failures in older vehicles. They also say it could lower gas mileage and void warranties of air-cooled engines used in outdoor power equipment and motorcycles.

The Engine Products Group has asked the Supreme Court to review a Court of Appeals decision that blocked a lawsuit aimed at stopping implementation of the 15% blend in gasoline pumps.

"It's a very big deal because we know that if E15 is in the marketplace, there will be engine failures," said Kris Kiser, president and CEO of the Outdoor Power Equipment Institute that represents Wisconsin firms Briggs & Stratton Corp., Kohler Co., Ariens Co. and others in the power equipment industry.

The petition asks the Supreme Court to allow the engine makers' case against the EPA to move forward.

"It's not in the interest of consumers to discover, after the fact, that engine performance problems are occurring because a new fuel was rushed into the marketplace," Kiser said.

A decision on whether the court will review the District of Columbia Court of Appeals ruling could come this summer, Kiser said, although a ruling might not come for two years.

Meanwhile, the rollout of E15 continues, albeit at a modest pace.

Some service stations in Iowa and other states now offer the blend, and Wisconsin is scheduled to get E15 this summer, probably in rural areas where ethanol has strong backing from farmers who grow corn used to make the biofuel additive.

The 15% blend could be a nickel or more per gallon cheaper than gasoline with the 10% ethanol blend, said Josh Morby, executive director of the Wisconsin Bio Industry Alliance.

"The thing that will drive this is consumer demand for cheaper gas," Morby said.

The risks of using E15 have been exaggerated, according to the American Coalition for Ethanol that says the fuel blend has undergone three years and millions of miles of testing by the EPA.

"I don't know if anything in this issue surprises me anymore. The oil industry has had full control over the nation's fuel supply for a century," said Ron Lamberty, the coalition's senior vice president.

The new fuel is not intended for outdoor power equipment such as lawn mowers, garden tractors, all-terrain vehicles and boats, and a required label on fuel dispensers will clearly state that.

Consumers aren't going to mistakenly use E15 in small engines, just like they wouldn't use diesel fuel, according to Morby.

"The reality is it isn't approved for use in these engines," he said.

But engine manufacturers aren't giving up their fight against E15 even if the Supreme Court doesn't rule in their favor. They are urging Congress to reverse the EPA's decision until the National Academy of Sciences does more engine testing.

"The fuel that you might legally put in your newer car or truck could literally destroy the engine in your boat, lawn mower or snowmobile," Kiser said. "Ever since the internal combustion engine was introduced in the marketplace, whatever gasoline that was available for your automobile or pickup truck was always safe to use in everything else. Now that's no longer the case."

Briggs & Stratton and other outdoor power equipment makers have been warning consumers not to use E15 in their products when it becomes available.

"Everyone is kind of preparing for it," said Ann Stilp, spokeswoman for Ariens Co., in Brillion.

About Rick Barrett

Rick Barrett covers manufacturing, telecom and agriculture. He has received Best in Business awards from the Society of American Business Editors and Writers and was co-recipient of a Barlett & Steele award for investigative business journalism.